The invention relates to a tracked chassis comprising a continuous track that comprises ground plates coupled so as to be rotatable to each other and which is guided by means of a driven sprocket having at least one toothed ring in order to drive the continuous track, wherein each individual ground plate has at least one hump link with hump link flanks oriented in the running direction of the continuous track, and wherein the hump links are designed to engage in recesses formed between radially protruding teeth arranged on the circumference of the sprocket while the continuous track circulates over the sprocket.
Conventional tracked chassis generally feature an additional running path that is respectively realized on the sprocket and on the continuous track and serves for supporting the track links on the sprocket, wherein the sprocket is supported on plane surfaces realized on the hump links either by means of the faces of the sprocket teeth and/or of a circumferential surface realized on the sprocket.
A tracked chassis with the initially cited features is known from DE 44 44 982 A1, wherein the sprocket is supported on the track links with the faces of its sprocket teeth in this design of a tracked chassis such that a corresponding running path is formed.
The continuous track of the known tracked chassis is realized in the form of a so-called hump links track, in which a hump link (shoe) with hump link flanks (shoe noses) that are aligned in the moving direction of the hump links continuous track is respectively arranged on the individual ground plates of the continuous track. In this case, the individual ground plates are directly coupled to one another by means of engaging or overlapping areas and bolt connections engaging therein. If the hump link continuous track is guided over a driven sprocket (driving drum) in order to be driven, the shoes engage into intermediate spaces between sprocket noses (sprocket teeth) on the driving drum and are taken along by the sprocket noses during the rotation of the driving drum. In the known tracked chassis two spaced-apart sprockets are provided and hump links (shoes) on the ground plates that are spaced apart by the same distance are respectively assigned to said sprockets. The sprocket noses, as well as the shoes, have relatively steep shoe noses engagement surfaces or shoe noses that respectively extend in an arc-shaped fashion such that a form-fitting engagement between the shoes and the intermediate spaces between the sprocket noses on the driving drum is always ensured when the shoes and the sprocket noses have an identical pitch and the shoes of the hump links continuous track are taken hold of and pushed along by the opposing shoe nose engagement surfaces of two adjacent teeth.
DE 44 44 982 A1 also mentions a common problem occurring on a tracked chassis of this type, namely that a wear-related elongation of the hump links continuous track is associated with an increase of its pitch as the operating time of the tracked chassis increases. In the described design of a tracked chassis, this leads to a restraint of the individual shoes in the recesses of the driving drum such that the wear on the shoes and on the sprocket noses is increased. In order to improve the functionality of the tracked chassis without having to completely disassemble the tracked chassis, the sprocket noses are arranged on the driving drum separably and with an adjustable radial distance from the driving drum such that the distance between the shoe nose engagement surfaces of the sprocket noses can be increased by displacing the sprocket noses radially outward and therefore adapted to the increased distance between the shoe noses when the hump links continuous track is elongated. In this way, the running path formed by the faces of the sprocket teeth or sprocket noses can be preserved.
The known tracked chassis has the disadvantage that the position of the sprocket noses on the sprocket needs to be corrected if an elongation of the track occurs, wherein this correction is associated with a corresponding effort. Furthermore, the known arrangement does not completely eliminate the track restraint problem during the engagement with the sprocket because the direct bolt connection between the individual ground plates makes it impossible for an individual ground plate to align itself to the position of the sprocket noses during its circulation over the driving drum since its position relative to the driving drum is influenced by the position of the leading ground plate, as well as the position of the following ground plate. Consequently, an inclined position of the ground plates with the shoes arranged thereon cannot be precluded and also not compensated if it occurs.
DE 44 21 001 A1 already discloses a drive system for a continuous track, in which the sprocket features a running path for the ground plates of the hump links continuous track in the form of outer circumferential surfaces to both sides of its cylindrical driving bodies. The track links engage into the recesses formed between the cylindrical driving bodies with triangular teeth provided on the track links such that a linear contact of the driving bodies on the teeth flanks results. In this case, the individual track links are connected to one another by means of connecting sideplates, the fastening of which on the connected track links respectively defines rotational axes for the pivoting motion of the teeth that successively engage with the driving bodies of the sprocket during the approach. In the known drive system, it is attempted to prevent wear by reducing the occurring vibrations with an arrangement of rubber mountings for the driving bodies and rubber bandages for the running surfaces. The behavior of the track in case of an elongation thereof is not discussed.
Furthermore, DE 22 59 352 A describes a track drive for vehicles, in which the teeth of the sprocket and the hump links of the track links have an angular shape with linearly extending teeth flanks and hump link flanks, but in which an additional running path is formed analogous to the tracked chassis described in DE 44 44 982 A1 due to the contact of the faces of the sprocket teeth with separate support surfaces on the hump links of the track links, wherein the teeth heads of the sprocket teeth end on a diameter that is concentric to the sprocket and defines the running path. Since power is transmitted due to the respectively contacting surfaces of the sprocket teeth and the hump links, two geometrically independent surfaces are required for driving and for guiding the track in a track drive of this type.